Launching a suprise attack to create a major break in German lines, over 400 tanks rolled across no man's land and into the Hindenburg defences, where they proceeded to lay heavy fire down the length of the trenches and roll up the flanks of the penetration.

By 4pm the tanks had advanced seven miles, affecting the most rapid advance of the war. To put this in perspective, a similarly sized penetration had taken three months and cost 250,000 casualties.